I'm driving a 2018 Prius Prime (plug-in). What do you want to know about it?

[aerohead]

My longest round trip local commute is 16-miles.I've got a zero-carbon wind option from the electric co-op.Even at the 4/5ths charge and 22-miles range,that would cover all my local commuting,and carbon-free potential.Between East Albuquerque,New Mexico,and Archer City,Texas I counted about 1,300 spinning wind-farm turbines from a Southwest Airlines flight last month.Interesting times!
Also,there was a 80-mile range,$3,400, SMART EV available in Nashville,Tennessee not long ago.It's beginning to look like I'll be able to join some of you in this EV experiment after I get the pickup project behind me.

[MetroMPG]

If any EV needs a boat tail, it's a Smart!

[aerohead]

Originally Posted by MetroMPG

If any EV needs a boat tail, it's a Smart!

That's the understatement of the decade! And I'm a sick enough puppy to take that on! Somewhere online there's shot of a Smart towing a sailplane trailer.It's truly twisted!

[Xist]

This is the largest that I can find:

[MetroMPG]

I accepted the Prius bribe to look after my friends' house & pet again for a few days. This time I'm learning more about the cold weather behavior of the car...

For example: it was -18C / 0F when I went to use it, and the engine fired almost immediately on power-up. So I shut if off, made sure it was in EV Mode before I turned it back on, but the ICE fired again.

So it burned dinosaurs along most of the subsequent ~28 km drive. (While using about 20% of the pack capacity.) I even stopped part way through the drive & switched it off & on again to no avail.

I don't think it was heater demand because I turned the temp & fan settings down and the defrost off, yet the ICE continued to run.

Possibly due to battery pack temperature? The car had been sitting for several days - a true cold soak. And the pack was full, so it didn't benefit from the heat of recent charging.

Coincidentally, a Chevy Bolt went by in the other direction while I was puzzling over the Prius ICE and I thought: they're sure not having this problem!!

[redpoint5]

If it's like the first plug-in model, you've got to turn the heat all the way to the lowest setting to prevent the engine firing up. Did you try turning the HVAC off altogether? Any window defrost setting will probably fire up the engine too... I've been loaning out my Prius for the past 6 months so I'm losing some of my operating knowledge.

The Bolt suffers a tremendous range penalty by running the resistance heater. I think it pulls something like 2 kW until the set cabin temp is reached, and then still has a large draw to maintain it. The Bolt will also use its battery energy to keep the pack temperature above freezing as long as it has at least 40% charge. It uses wall power to maintain temp while plugged in, and that can represent a fairly significant extra consumption in the winter in unheated garages or especially if kept outdoors.

Anyhow, when my Prius fires up the ICE for any reason, it stays on until 130 F coolant temp is reached. Initially it uses battery power only as the engine warms up to some minimum amount, I'm guessing to reduce pollution as the cat and engine comes up to temp. It is annoying to burn fuel and get nothing from it other than heating.

[MetroMPG]

The Prime has a heat pump, and it will provide cabin heat in EV mode without firing the ICE. I've seen it work that way in this car, although it was in milder ambient temps.

I'm sure there's some combination of battery pack temp, ambient temp and high HVAC settings that will cause the ICE to fire regardless of state of charge.

I could just RTFM, of course.

Anyhow, when my Prius fires up the ICE for any reason, it stays on until 130 F coolant temp is reached.

If you completely shut down the car before hitting 130 F and powered up again, would it re-fire? Or would it think the coolant is just cooling down from the last time the engine was used, and leave it alone?

I tried stopping/rebooting twice on today's trip, and it didn't make any difference -- engine re-fired each time, and it was definitely at full operating temp before the 2nd reboot.

[Vman455]

It might be just because of ambient temperature. The heat pump can only be used down to 14F, so anything below that and it might default to running as a hybrid.

My parents bought a Prime last month; they love it so far. My dad keeps emailing, "The car got xx.x mpg today!"

[redpoint5]

Originally Posted by MetroMPG

If you completely shut down the car before hitting 130 F and powered up again, would it re-fire? Or would it think the coolant is just cooling down from the last time the engine was used, and leave it alone?

I tried stopping/rebooting twice on today's trip, and it didn't make any difference -- engine re-fired each time, and it was definitely at full operating temp before the 2nd reboot.

If I turned off the HVAC or set it to the lowest setting, then it would not fire up the engine upon restart.

Any chance it was a scheduled engine run? I know the Volt will run the engine every so often if it hadn't run recently.

[MetroMPG]

I think Vman may be on to something, because I briefly saw a message on the display (not long enough to actually read it, though) that said something about "-10 C", which just happens to equal 14 F.

I have since taken the car on another errand, with a bit of prior charging (since the initial no-EV trip) and it's behaving as expected now.

However...1) Ambient temp is now above -10 C, and 2) recharging would have warmed the pack. So it could be either/both.

---

EDIT: Vman is correct...

If you have the heater on and the outside temp is below around 14 degrees F, EV mode may not be available. Or when the windshield defogger is running. p.87 Owners Manual

https://priuschat.com/threads/ev-mod...eather.189096/

I didn't completely turn off HVAC - I only put it on the lowest fan setting and reduced the target temp.

The pack temperature CAN affect the car in a big way, but it wasn't this cold...

the Prius owner’s manual states, “When the hybrid battery (traction battery) is extremely cold (below approximately minus 22 degrees Farenheit [minus 30 degrees Celsius]) under the influence of the outside temperature, it may not be possible to start the hybrid system. In this case, try to start the hybrid system again after the temperature of the hybrid battery increases due to the outside temperature increase, etc.”

https://www.cars.com/articles/how-do...1420692904443/

In other words, a Prime may be utterly useless in seriously cold weather!